Clancy, 66, was “America’s, and the world’s, favorite international thriller author,” his website states. Throughout his career, he wrote more than 20 books, most of which were novels centering around the Cold War, and 17 of which were New York Times #1 best-sellers. Along with J.K. Rowling and John Grisham, Clancy is one of three authors who sold two million copies of a book on first printing.

His wrote his first book, The Hunt for Red October, while he was an insurance salesman, the Times reports, and sold it for just $5,000 in 1985.

Mr. Clancy was praised for his mastery of technical details about Soviet submarines and weaponry. Even high-ranking members of the military took notice of the book’s apparent inside knowledge.

In an interview in 1986, Mr. Clancy said, ”When I met Navy Secretary John Lehman last year, ”the first thing he asked me about the book was, ‘Who the hell cleared it?’ ”

His recurring characters include Jack Ryan, a CIA agent, and John Clark, who Clancy considered the “dark side” of Jack Ryan. He also co-created two additional novel series, the Op-Center force and the Net Force, which were written by others.

Several of his books have been adapted to film, including The Hunt for Red October, Patriot Games, Clear and Present Danger and The Sum of All Fears. In 1996, he co-founded a video game company called Red Storm Entertainment, although his direct involvement with creating the games, which are based on his books and plot-lines, is not clear.

His final book, Command Authority, is scheduled for release on December 3.